The control of the thickness of a tire is important also from the viewpoint of detecting a defective product. However, conventionally, there has been no method of measuring the thickness of a tire around the tire with ease, and usually the thickness has been evaluated by sensory inspection by an operator. As a method of measuring the cross section of the tire by a non-destructive inspection, for example, a method using a CT scanning is known (see, for example, Patent Document 1).
Further, as a technique of non-destructively measuring the thickness of the cross section of a tire, for example, Patent Document 2 discloses a tire thickness measurement tool comprising a non-contact type displacement sensor on the tip of an axis thereof which is inserted into the tire, wherein the thickness of the tire is measured based on the distance to the inner surface of the tire measured by the above-mentioned displacement sensor. Still further, as a technique of a tire shape inspection, Patent Document 3 discloses a tire shape inspection method and an apparatus thereof which can remove a knurling portion from the tire side portion and precisely detect the outer surface shape of tire side portion, and Patent Document 4 discloses an apparatus for creating a reference shape data for inspecting a tire in which the three-dimensional shape data of a split mold inner surface which vulcanizes and molds a tire is obtained and a reference shape data for inspecting a tire is created, respectively.